How to have vertical stripes across whole object?
While in front orthographic view, you could select all in edit mode with A &gt; press U &gt; and click Project From View. Your UV will then appear the same as the object does in front view, so the Wave Texture will be vertical while using the UV Coordinates. You can use the Mapping node to change the scale of the stripes.

Alternatively, you can use the Object Coordinates. If you haven't applied your object's rotation, you can use the Mapping node to rotate the stripes accordingly.